Spline and seat connector assemblies

ABSTRACT

A continuous spline and seat connector assembly that is adapted for use in the construction of buildings such as housing. The spline may be inserted into a seat member in the direction of the depth of the seat member and its removal opposed by a locking action which occurs after the insertion of the spline.

United States Patent Inventor Appi. No. Filed Patented John H. Brenneman 389 Prospect Ave., Princeton, NJ. 08540 859,230

Aug. 13, 1969 Dec. 14, 1971 Continuation-impart of application Ser. No. 837,495, Sept. 1, 1959, now abandoned and a continuation-in-part of 514,573, Dec. 17, 1965, now abandoned which is a continuation-in-part of application Ser. No. 513,652, Nov. 26, 1965, now abandoned which is a continuation-in-part of application Ser. No. 174,554, Feb. 20, 1962, now abandoned. This application Aug. 13, 1969, Ser. No. 859,230

SPLlNE AND SEAT CONNECTOR ASSEMBLIES 20 Claims, 24 Drawing Figs.

U.S. Cl 287/20.92B, 85/7, 52/584 Int. Cl Fl6b 5/07 Field of Search... 85/7,5, 8.8;

287/2092 B, 20.92 T, 20.92 R; 52/584 [56] References Cited UNITED STATES PATENTS 559,924 5/l896 Arnold 287/2092 B 947,602 l/l9l0 Stahl et al. 85/8.8 l,576,527 3/]926 McBride... 85/5 2,909,957 l0/1959 Rapata 85/5 3,251,260 5/l966 Serdechny 85/7 1,723,306 8/1929 Sipe 287/2092 K 3,363,383 l/l968 La Barge 52/584 FOREIGN PATENTS 651,985 ll/l962 Canada 85/7 Primary Examiner- Edward C. Allen Attorney-Burns, Doane, Swecker & Mathis ABSTRACT: A continuous spline and seat connector assembly that is adapted for use in the construction of buildings such as housing. The spline may be inserted into a seat member in the direction of the depth of the seat member and its removal opposed by a locking action which occurs after the insertion of the spline.

PATENTED DEC] 4H1?! F INSERTIO SPLINE SEPARKTION COMPRESSION SEAT J22 F WITHDRAWAL COMPRESSION-* SEPARATION SEAT SPLINE SHEET 2 BF 4 John H Brenneman ATT RNEYJ PATEr-mnmmmn 1627,1362

SHEET 3 OF 4 4 xik /i/r-a NORM AL EXPANSION mssrmou coNTRAcT'o" I38 John H. Brennemon M WWW 7/440 f5 ATTORN ,5

PATENTEU DEC 1 4 ml SHEET 0F 4 INVENTOR John H Brennemon BY M, m,

M, g ATTOENEYS SPLINE AND SEAT CONNECTOR ASSEMBLIES This application is a continuation-in-part of my application, Ser. No. 514,573, filed Dec. I7, 1965. now abandoned, which is a continuation-in-part of my application, Ser. No. 513,652, filed Nov. 26, I965, now abandoned, which in turn is a continuation-in-part of my application, Ser. No. 174,554, filed Feb. 20, 1962, now abandoned. This application is also a continuation-in-part of my application, Ser. No. 837,495, filed Sept. 1, 1959, now abandoned.

This invention relates to a continuous spline and spline seat connector assembly adapted for construction of buildings, cabinets, and the like which will be suitable to form a strong durable architectural joint which will satisfy mechanical strength requirements for large structures.

Splines have been used for many years in the building trade as tools of alignment, their most notable use being as inserts in glued joints or in ceiling or roof panels to preclude the sagging or uneven deflection of the structural materials used. Usually, however, it has been considered necessary to use a device or material other than the spline for fastening purposes. For example, nails and/or glue are commonly used to join interior wall or ceiling panels though, in such cases, it has usually been necessary to leave one side of the panels unfinished so that the nailing or gluing operation might be properly performed. In those cases where the panels have been completely prefabricated during manufacture, it has been necessary to use some external fastener device such as a batten or nails to join them and to finish over any nail holes or other exposed fasteners.

Many construction methods devised to date using prefabricated wooden panels have necessitated substantial onsite labor for the construction of a given unit, even where small or light buildings are involved. In addition to the added cost in high-priced labor areas, such methods have required the use of cumbersome and time-consuming construction methods, such as drilling, gluing, hammering, driving screws, etc., all of which tend to injure the materials of construction to a greater or lesser degree and/or require additional finishing operations.

It is a principal object of this invention to provide an improved spline and seat connector joint assembly. In such joints the sidewalls have a plurality of mating projections which provide a snug, tight joint and a spline member and seat member are so constructed as to enable assembly in a direction perpendicular to the direction of the longitudinal axis of the slot and spline by forming the sidewalls of one or both of the members to have sufficient deflection without permanent deformation as to enable the spline to be inserted in the seat and the mating projections to engage so as to resist a force tending to remove the spline from the seat.

Another object is to provide a variety of novel spline configurations which are adapted for use in the connector joint assembly of the present invention.

A still further object is to provide a variety of novel spline receiving seat configurations which are adapted for use in the connector joint assembly of the present invention.

These and other objects of the invention will become more fully apparent from the claims, and from the description as it proceeds in connection with the appended drawings wherein:

FIG. I is an end view of an elongated spline member formed in accordance with the present invention;

FIG. 2 is an end view showing the spline member of FIG. I inserted in an upper seat member which may be a slotted block of wood and showing a second seat member similar to the other seat member adapted for insertion on the exposed end ofthe spline member;

FIG. 3 is an end view of a spline seat that has been extruded from a material such as aluminum or plastic;

FIG. 4 is an end view of a further embodiment of a spline member incorporating certain principles of the present invention;

FIGS. 5 through 9 are end views of other spline members which incorporate various principles of the present invention;

FIG. 10 is an end view of a spline member similar to the spline illustrated in FIG. 5 but inserted in two seat members that are held in abutting relationship by the spline;

FIGS. 11 through 14 are pictorial views of difierent spline members having varying types of toothlike projecting surfaces in accordance with the present invention;

FIGS. 15 and 16 are diagrammatic illustrations of the action of the seat wall and spline wall during insertion and attempted withdrawal respectively;

FIG. 17 is a transverse sectional view of a novel flexible seat member that is adapted to be inserted in a longitudinal slot along a post, beam or edge of a panel, or to be cast into a material such as concrete;

FIG. 18 is an enlarged view of the spline seat of FIG. 16 in a wooden structural member showing the spline member in position;

FIG. 19 contains four diagrams illustrating the action between teeth 136 on the sidewalls of the seat member and teeth 142 on the lower side of flaps 138 on the seat member of FIG. 17;

FIG. 20 is a transverse sectional view of a further embodiment of a flexible seat member constructed in accordance with the present invention;

FIG. 21 is a transverse sectional view of a still further embodiment of a flexible seat member constructed in accordance with the present invention;

FIGS. 22 is a view, to an enlarged scale, of a portion of the novel seat member illustrated in FIG. 21, showing the manner in which the seat member sidewall deflects when the spline member is pushed into the spline seat;

FIG. 23 is a view similar to FIG. 22 and shows the manner in which the spline-engaging sidewalls of the seat member deflect when a force tends to pull the spline member from the seat member; and

FIG. 24 is a transverse sectional view showing a spline member engaging a pair of seat members each similar to the seat illustrated in FIGS. 21 through 23.

The basic spline connector of this invention is illustrated in FIG. I and in a preferred form may consist of an elongated member 20 having a generally rectangular cross section with end walls 22, sidewalls 24 and a hollow interior. Such a spline member can be extruded from aluminum or other suitable material and cut into pieces having lengths that are, for example, 8-feet long when used in connection with the erection of walls that are S-feet high. A plurality of outwardly extending, tooth like projections 30 are provided on the outer surfaces of walls 24 which have a generally inclined leading surface 32 and a trailing surface 34 which is disposed at an acute angle with the surface 32. The intersection of leading edges 32 and trailing surfaces 34 may form biting edges on sidewall exterior surfaces 24. The upper and lower halves of the spline element as shown in FIG. I may be identical and dimensions in inches of a typical spline element are as follows: A=0.600; B=0.655; C=0.660; D=0.663; Er -0.666; F=0.080; G=0.l50; and I-I=0.68. The distance between the inside surfaces of sidewalls 24 may be approximately one-half inch and the wall thickness of the arcuate end walls 22 approximately 0.06 inches.

Referring now to FIG. 2, the spline member 20 is shown already driven into a slot in a wooden seat member 36, such as a 2-by-4 that has a length perpendicular to the plane of the drawing, and a second seat member 38 is illustrated in position to be driven onto the exposed lower half of spline member 20 so that when assembled, surfaces 40 and 42 of seat members 36 and 38 will be in abutting relationship. Slot 44 in seat member 38 has parallel sidewalls 46 which may be formed by a saw cut or dado blade in wood or other sawable material. The slot width should be slightly less than the 0.6 nominal width of the spline member 20, the exact amount depending somewhat on the relative compressibility of the wood fibers.

Where spline member 20 is made of a hard material like aluminum, the spline may be driven as by hammer blows into the slot of seat member 36. Alternatively, a board may be forced against the spline member with one or more blows to more uniformly distribute the insertion force against face 48 of spline to avoid deforming the edge of the spline. During such insertion, the walls 46 of the slot in the seat member are urged apart and the walls of spline member 20 having the toothed projections are compressed inwardly, but without permanent defomiation of either the spline or seat member. Thereafter, a force tending to remove spline member 20 from the slot causes the projections on the spline to bite into and in effect, form mating projecting surfaces on sidewalls 46 of the slot in the seat member. Where sufficient force to remove spline member 20 against the holding power of the teeth has been applied, the seat member has been found to fracture along grain lines of the wood. Thus, when two seat members 36 and 38 are secured together in abutting relationship by spline member 20, a firm joint is provided which will not fail under normal loads. Because the seat member is normally 4 inches or so, resistance against tilting of one seat member relative to the other is provided.

To assemble seat member 38 over the exposed end of spline 20 after it has been inserted in seat member 36, difficulty is sometimes encounteredparticularly if seat member 38 is an edge frame on a 4-by-8-foot panel. In such case, the impact force for insertion must be applied at least 4 feet from spline member 20, and the force impacts may be attenuated by the panel so much as to prevent assembly. In such case, a saw cut 50 (see FIG. 2) running longitudinally of the spline has provided increased resilience and flexibility in the spline member so as to enable seat member 38 to be placed in position. Since the teeth are shaped to lockingly engage the side wall surfaces 46 of slot 44 in seat member 38, sufficient holding force is provided even though the spline member has been cut by slot 50.

In a building system it is also desirable to use structural frames made of materials other than wood. Panels can be formed with four edge frame members serving as the perimeter, and panels attached into place on either side to form a wall. For the edge frames, I have found certain configurations can work effectively as seat members for the splines of this invention.

Referring now to FIG. 3, a seat member 52 adapted to receive one-half of the spline member 20 of FIG. I is illustrated which may be used as an edge frame member for a beam, post or panel. Seat member 52 may be formed by extruding from a suitable material such as aluminum, and be provided essentially with spaced sidewalls 54 and 56 that are capable of a slight separation. In the illustrated embodiment, seat sidewalls 54 and 56 are joined by an end section 58 which is U-shaped and dimensioned so as to provide a resilient, flexible lateral displacement of sidewalls 54 and 56 without permanent deformation. End extensions 60 and 62 on opposite sides of the seat member may be of any suitable size or shape as may be determined by the requirements of the beam, post or panel.

If the seat member is formed of a material such as aluminum or a hard plastic building material, or if the spline member is formed of a synthetic plastic material or other comparatively soft material, the toothlike projections on spline member 20 will not lockingly engage the slot wall surfaces if smooth wall surfaces are provided. Therefore, in such cases, the seat member sidewalls should have surfaces which can lockingly engage with the toothlike projections on spline member 20. For this reason, the seat member of FIG. 3 is provided with toothlike projections 64 which may have a shape similar to the corresponding projections 30 on spline member 20. The spacing of projections 64 must, of course, be such as to lockingly engage with projections 30 of spline member 20 and for the dimensions, M=0.62 and N=0.676 are representative values that are satisfactory where the thickness of arcuate section 58 is about 0.06 inches.

To provide a satisfactory spline and seat connector joint of the type described, it is important to have configurations that allow separation of the seat slot sidewalls and/or compression of the spline sidewalls all the way to the location where the leading portion of the spline seats into the seat member. Mere cantilever bending of the seat member about a hinge as at 66 of FIG. 3 would allow displacement of the mouth or upper end of the seat member slot, but would not allow the upper slot teeth to engage the corresponding spline teeth near the center portion of the spline when the spline is inserted completely into the slot. Unsatisfactory spline and seat member configurations result in pennanent deformation such as galling of the toothlike projections, bending beyond the yield point or fracture of one or more parts. Prior art spline and seat fasteners such as shown in Canadian Pat. No. 549,089 and Belgian Pat. No. 531,202 which superficially appear similar to the spline and seat connector assembly of the present invention are not satisfactory because of defects resulting from the absence of flexibility and resilience necessary to prevent permanent deformation.

Referring now to FIGS. 4 through 10, various configurations are illustrated which may be used as the cross section for the spline member in accordance with the principles of the present invention. In each of these embodiments, the spline has been rotated 90 from that illustrated in FIGS. 1 through 3 so that the direction of insertion is horizontal rather than vertical. In FIG. 4, the cross section resembles an H rather than a rectangle as in the embodiment shown in FIG. 1. The sidewalls at each end of the fastener contain the two finlike projections that are rigid and not easily deformed. The number of teeth illustrated in each sidewall is two; it should however be recognized that in some instances one tooth might be needed whereas other applications may require four or more teeth.

One advantage of the embodiment illustrated in FIG. 4 is that the sidewalls are more easily deflected toward each other than in the embodiment illustrated in FIG. 1. The sidewalls on both ends of the spline member are formed to deflect toward a central plane indicated by center line 68. It can be observed that the central plane 68 of the spline when it is located in a seat member coincides with the central plane of the seat member.

The spline embodiment in FIG. 5 is in the form of an S. The opposed teeth on sidewalls 70 and 72 can deflect toward each other upon insertion of the spline in a seat member. Similar deflection is provided for the teeth on side walls 74 and 76. The opposite end sections of the spline are joined together by a reverse curved portion 78 whose rigidity can be controlled by variation of its thickness. When subjected to a withdrawal force, the reverse curved portion 78 urges the spline walls outwardly against the seat sidewalls.

The spline element illustrated in FIG. 6 has a generally circular cross section with the opposed teeth on sidewalls 80 and 82 lying in arcuate paths. The teeth for the other end of the spline formed on sidewalls 84 and 86 lie in a similar arcuate path. As the spline is inserted in a seat member, the sidewalls will move in the direction of the arrows to thereby conform with the shape of the sidewalls of the seat member which may have a disposition other than parallel as will be discussed below.

In FIG. 7, a further embodiment is illustrated wherein the sidewalls 88 and 90 are joined by a central section 92 and corresponding sidewalls 94 and 96 are free end portions capable of deflecting in the direction of the arrows toward the other sidewall portions. In this embodiment, the toothlike projections are not in alignment since it is not essential in all applications that the two sidewall portions 90 and 96 for example be symmetrical.

FIG. 8 shows a further embodiment wherein the sidewalls containing the teeth are capable of deflection in the direction of the arrows as illustrated. The central section 98 is here shown as a flat plate; it should, however, be recognized that it may be formed with appendages such as a central stifiening ridge (not shown) running the length of the spline on one or both sides.

FIG. 9 illustrates an embodiment similar to that of FIG. 8 but having a T-shaped connector on each end. The connector on the left end portion 100 is illustrated to have three teeth on each sidewall whereas the connector on the right end portion does not have teeth on the sidewall surfaces 103, but instead relies on the end surfaces 104 for engaging a tooth in a seat member to lock the spline in position. FIG. 9 is also illustrative of a spline where the opposite ends are not identical.

FIG. 10 shows a further embodiment of a spline 105 which has a configuration similar to that of FIG. 5 inserted in a pair of seat members 106 and 107. Spline member 105 may be a sheet of steel or other resilient material which can be formed as by rolling to have an Sshaped configuration. The only locking surfaces on the spline are at its opposite ends 108. The seat comprises a rectangular or U-shaped slot with looking surfaces or laterally offset grooves 109 that may be formed on both sidewalls of the seat member so the spline can be inserted in either direction. The spline member 105 is formed with sidewalls 110 which each bridge across the gap between the seat sidewalls in seat members 106 and 107. This particular embodiment of the spline member can be very inexpensively manufactured and would be satisfactory for many applicatrons.

Referring now to FIGS. 11 through 14, there are here illustrated four spline members each having different types of toothlike projections which may be used in accordance with the present invention. In FIG. 11, the toothlike projections on the sidewalls comprise longitudinally oriented rows of parallel teeth 11] all of whose leading faces 112 slope upwardly toward the longitudinal center of the sidewalls. Trailing faces 113 of each of the toothlike projections form an acute angle with the leading faces 108 to provide a relatively sharp biting edge 114 on each of the teeth.

Thus, as can be clearly seen in FIG. 11, the sidewalls may be longitudinally divided into two substantially equal portions 115 and 116 which each have two sets of projections that are mirror images of each other. While the spline members may be readily formed of aluminum, it should be understood, however, that other materials such as plastic may be used especially in embodiments where the spline receiving seat slots have sidewalls with preformed intercngaging surfaces such as shown in FIG. 3. Where, however, the seat member is wood as shown in FIG. 2, it is necessary that the toothlike projections be made of a hard material such as metal, although the balance of the spline may be made of another material or a similar material but having different degrees of hardness.

In the embodiment illustrated in FIG. 12, the toothlike projections have concave or hollow ground, intermittent teeth in which alternating notches gouged in the teeth provide sharper punching power for use with wooden seat members as shown in FIG. 2 where the wood has pronounced hard and soft annual rings, such as in Douglas Fir.

FIG. 13 shows a spline member having a series of rows of intermittent, burrlike teeth having outstanding punching ability with respect to tough or variable hardness wood and plastic structural units. Such a section may be extruded with flat sides and the teeth may thereafter be cut in a separate operation by means of a gougelilte cutter adapted to raise extremely sharp edged burrs.

The spline member shown in FIG. 14 is provided with continuous, straight beveled teeth. This tooth configuration is similar to that illustrated in FIG. 11 except that its toothlike projections are more closely spaced than those in FIG. 11 and have a flat rather than concave or hollow ground leading faces. As in the case of the spline element of FIG. 11, this spline configuration is generally universally adaptable to various requirements, and because of its closely spaced, biting surfaces. it can ratchet into a seat having preformed teeth with double or triple the spacing as illustrated in FIG. 3.

Referring now to FIG. 15, and also to FIGS. 1 and 3, a fragmentary view of one side of the spline and one side of the seat illustrates the sidewall action in those embodiments of this invention where the sidewall of both the spline and the seat member have preformed teeth. The insertion of force F on the spline causes sloping surfaces to engage as illustrated in FIG. 15 and produce opposed forces tending to separate the seat sidewalls and to compress the spline sidewalls. The teeth must be sufficiently rigid to avoid permanent deformation as by crushing during insertion.

FIG. 16 illustrates the action resulting when a force is applied tending to remove the spline after it has been inserted in the seat member and the interlocking surfaces 120 on the spline have engaged the corresponding surfaces 122 of the seat.

If surfaces 120 and 122 are at right angles relative to the direction of insertion and removal, fracture of the teeth will be required for removal unless the teeth slide apart as during insertion. However, if the slope of surfaces 120 and 122 is slightly more than as illustrated in FIGS. 14 and 15, then a force tending to cause withdrawal can produce force components tending to compress the seat sidewalls together and also to separate the spline sidewalls. This action tends to increase the area of locking engagement between surfaces on the spline and 122 on the seat, thereby producing a joint of even greater holding power, and of course, eliminating the possibility of the teeth sliding apart. On the other hand, the locking surfaces 120 and 122 of the teeth may be sloped to allow removal of the spline from the seat member with a predetermined pulling force to facilitate assemblies which are intended to be taken apart and reassembled.

For representative dimensions as given in connection with the spline of FIG. I where the width is approximately 600 mils and the tooth depth is approximately 30 mils with a reasonable tolerance from the extrusion die which may be :10 mils, the tooth dimensions are limited by the strength of the material from which the spline and seat member sides are formed, against crushing if the sharp ends of the teeth are to be reasonably protected against bending over or galling. Also important is the force required to separate the seat walls and/or compress the spline walls by a distance of 30 or 40 mils necessary to permit assembly of the spline in the seat. Since in some applications the spline element must be comparatively strong and hence its sidewalls cannot be made to provide the requisite displacement, it becomes desirable to provide seat members with walls which can separate sufficiently far to permit the use of such comparatively rigid spline members without sacrificing the strength or other requisite properties of the spline and seat connector assembly joint.

Other embodiments of the seat member of this invention which may be used with the spline members described. and which have particular utility with the splines having the more rigid structural configurations are shown in FIGS. 17 through 25. In FIG. 17, a seat member is separately illustrated which may be used as an insert in a structural member as illustrated in FIG. 18. Seat member 130 of FIG. 17 has a substantially rigid end wall 132 and sidewalls 134 which are extruded or other wise formed from a thick plastic such as the polyformaldehyde resin produced by E. I. Dupont and Co., under the trademark Delrin. Other suitable flexible plastic materials are acetal resins, urethane or polyurethanes, polyethylene, nylon, vinyl chlorides or vinyl chloride acetate.

The inner surfaces of sidewalls 134 may be provided with inwardly projecting serrations or teeth 136 along their upper portions and flaps 138 attached to the upper end of sidewalls 134 by means of integral hingelike tongues 140 which initially hold flaps 138 inwardly toward the longitudinal axis centerline of seat 130. Flaps 138 are shown in their normal position in FIG. 16 (i.e., when there is no spline connection in the seat). The flaps may advantageously, though not necessarily, form a closure and prevent undesired foreign material such as pieces of concrete from becoming lodged in the seat prior to insertion of the spline member.

The lower surfaces of flaps 138 carry a plurality of teeth 142 for cooperating with teeth 136 on the seat sidewall when flaps 138 are forced downwardly and outwardly by insertion of a spline fastener 131 (FIG. 18) into seat 130 as will be explained. The upper surfaces of flaps 138 are similarly provided with upwardly extending toothlike projections 146 for cooperating with the projections on spline fastener 131.

The lower surfaces of flaps 138 are spaced slightly from sidewalls 134 when spline fastener 131 is fully inserted in seat 130 as illustrated in FIG. 18. This spacing enables seat flaps 138 to separate during insertion of spline fastener 131 to provide the desired resilience and flexibility without defonnation. Upon attempted withdrawal of spline fastener 131, the trailing surfaces of the spline teeth lockingly engage the trailing surfaces of flap projections 146 pulling the flaps upwardly and causing flap teeth 142 to cam against seat sidewall teeth 136 thereby moving seat flaps 138 toward each other and tending to lock spline fastener I31 firmly in position and resisting its withdrawal from seat member 134. Seat 130 may be inserted into a slot in any suitable material and still, through flaps 138, provide sidewalls which separate resiliently and without permanent deformation to secure spline 131 in position.

FIG. 19 illustrates diagrammatically the configuration of the flaps for various phases of loading. When spline fastener 13] is forced into the seat, flaps 138 fold or bend back against sidewalls 134 to physically engage serrations or teeth 142 on flaps 138 with a serrations or teeth 136 on seat sidewalls 134. This provides a desirable property of resilience and flexibility for the spline member as it engages the sidewalls of seat member 130 during insertion. The mating teeth 142 and 136 permit limited action illustrated in FIG. 19 between a flap 138 and sidewall 134. When the spline member is placed in position to cause only a normal load," a small space is provided between teeth 136 and 142. When the spline is inserted, teeth 136 and 142 are compressed tightly together. When a force is encountered which tends to expand the joint or to pull the spline from the seat, action designated Expansion occurs. When a force tending to contract the joint is encountered, the limited action designated as "Contraction" occurs. These comparatively small movements prevent weakening of the holding strength of the joint and reduce the likelihood of damage to the other components in the system.

While the foregoing discussion assumed that flaps 138 would fold or bend when the spline is inserted, the flap may be formed originally with a weakened cross section along a line at 140 so that a fracture occurs and flaps 138 would thus be fractured into a separated member. Alternatively, the seat member 132 may be originally formed without flaps, and thereafter inserts that have the-shape of flaps 138 may be placed between one or both of the seat sidewalls and the spline sidewalls. Such an arrangement can be used with seat members and spline members which both are so rigid and inflexible as to not work satisfactorily since the lateral deflection and locking action are in significant part provided by flaps 138.

FIG. illustrates a flexible seat member which is especially adapted for use with wooden structural components or with components having a wooden edge frame combined with other structural materials. An inwardly directed hatshaped slot 150 is cut in the wooden component or edge frame member 152 to receive a seat member 154 which may be made of any of the suitable plastic materials noted above in conjunction with the flexible seat member illustrated in FIGS. 17-19 or of a metal such as aluminum or steel, for example, having sufficient elasticity.

Seat member 154 is provided with sidewalls 156 having smooth outer surfaces at front flange portions 158 that are used to secure seat member 154 to the frame member as with an adhesive (not shown) or screw fasteners 160, for example. The inner surfaces of the sidewalls 156 may be provided with one or more teeth 162 which are adapted to engage spline member teeth and the sidewalls 156 are formed to have resilience to permit the spline member to be driven into its locking position by a sidewall construction that includes voids 168. The size of the voids in the wall between teeth 152 and void 154 are selected by taking into consideration the properties of the materials used to provide the requisite resilience. As previously discussed, the use of a larger number of smaller teeth on the sidewalls of the seat member 154 than the spline connector has, offers the advantage of the ratchet locking action and can decrease the requirements of the magnitude of deflection necessary for assembly and yet provide adequate strength for many applications.

A further embodiment of a flexible seat member in accord with the present invention is illustrated in FIG. 21. The seat member is here illustrated as an edge frame in a panel, post or beam that has veneer surfaces 172 and 147 on opposite sides and a serpentine layer 176 serving as a gasket on both sides of the spline seat.

The spline seat sidewalls 178 and 180 are formed with spline engaging teeth 182 and are supported from the seat element 184 which has two sidewalls 186 and 188 secured to the structural element 170, by connecting links 190 and 192. The end portions of connecting links 190 and the adjoining end portions of the seat sidewalls 178 and 180 are tapered to a reduced cross section so that the intersections of the connecting links with the seat sidewall will have relative pivotal movement to thereby act as a hinge at point a." A similar construction provides a hinge at point b." The rear or inner edges of seat sidewalls 178 and 180 are joined to seat member 184 by an L-shaped link 192 having legs 194 and 196. The links are so formed as to provide a hinge action at points 0" and d." The above-described members are arranged substantially in the form of a parallelogram with the fixed seat sidewall and the spline-engaging sidewall forming one pair of substantially parallel walls and the end links 190 and 192 providing the other pair of walls, albeit not precisely parallel. While the points a" through d" are shown in FIG. 21 only on for sidewall 180, the construction is advantageously symmetric and is the same for sidewall 178.

The spline-engaging sidewalls 178 and 180 may be bowed toward the center of the seat member recess and have formed thereon a large number of small teeth 182, as illustrated, for engaging the toothlike projections on the spline connector. The spacing of the teeth as illustrated in FIG. 24 is such that there are exact integer multiples of teeth 182 for every spline tooth.

Referring next also to FIG. 22, when the spline member is forced into the slotlike recess of the seat member, the action is such that spline-engaging walls 178 and 180 are forced apart, which is upwardly as viewed in FIG. 22, by the toothlike pro jections on the spline acting against teeth 182 on sidewalls 178 and 180. Because of the angles between sidewalls 178 and 180 and the connecting links 190 and 192 by which they are connected to the fixed portion of the seat member 184, sidewalls 178 and 180 deflect apart and toward the left in the direction of arrows A from the dotted-line position to the position shown in full lines as shown in FIG. 22. When the spline is forced further toward wall 184, sidewall 180 will move between the two positions shown in FIG. 21 as teeth 182 slide across the spline teeth. By using a larger number of smaller teeth 182 on the sidewall 180 than is used on the spline member as illustrated in FIG. 24, a ratchet action is achieved and the displacement between the two positions shown in FIG. 22 is reduced. For this purpose, the same result may be achieved by having the larger number of smaller teeth on the spline rather than on the spline seat as illustrated.

When the spline is fully inserted, the sidewalls 178 and 180, due to their inherent resiliency, snap back against the spline with teeth 182 on the seat sidewalls I78 and 180 engaging the toothlike projections on the spline, thereby pulling the spline further forward into the spline receiving recess of the seat member thereby insuring a snug, tight joint. At the end of this "snap back" movement, the locking members will be in the position shown in FIGS. 22 and 24.

Referring now to FIG. 23, action is illustrated for the situation where a force is applied for removing the spline from its seat member. When a separating force is applied, legs 194 and 196 of link 192 are placed in tension thereby swinging away from their dotted-line position next to the fixed portion of the seat member, allowing sidewalls 178 and 180 to move toward each other in the direction of arrow B in FIG. 23 and thereby forcing the lower section 181 of side 180 inwardly toward the center of the seat member recess and, therefore, more tightly against the spline. During this sequence, links 190 pivot in the direction of arrow A pulling the upper sections of sidewalls 178 and 180 away from the spline. However, at the same time, the sidewalls 178 and 180 are distorted from the substantially straight configuration of FIG. 22 to their normal inwardly convex shape (see also FIG. 21), thereby maintaining a tight gripping contact between the lower sections of sidewalls 178 and 180 and the spline.

FIG. 23 illustrates in section a spline 200 as it appears when securing two structural members 202 and 204 together, the action of the seat members during the insertion step having been described in connection with FIGS. 21-23. Once the assembly is completed, the joint is permanent and cannot be disassembled normally without damage to one or more of the parts.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

lclaim:

1. A spline and seat connector assembly comprising:

a longitudinally extending spline member having a closed peripheral wall and a hollow interior, said peripheral wall having two sidewalls symmetrically disposed on opposite sides of a central longitudinal plane, said sidewalls having outwardly facing surfaces containing two sets of longitudinally extending, rigid, toothlike projections on each of said sidewalls, a first set of projections defining one end of said spline member, and a second set of projections defining the other end of said spline member, the locking surfaces of the projections on opposite ends of said spline member being reversely disposed;

a longitudinally extending seat member having a longitudinal axis lying in the same longitudinal plane as the central longitudinal plane of the spline member comprising a pair of sidewalls on opposite sides of said longitudinal plane and defining a spline member receiving recess, said sidewalls having inwardly facing surfaces provided with longitudinally extending, rigid, toothlike projections with locking surfaces engaging the locking surfaces on said spline member,

said seat member sidewalls being spaced apart by a distance substantially equal to the distance between said spline member sidewalls; and

said assembly being characterized by said spline and said seat members having a combined sufficient resilient deflection of their respective sidewalls to enable insertion of the spline member into the desired locking engagement position in the seat member by movement of said spline member relative to said seat member parallel to said longitudinal plane in a direction normal to said longitudinal axis without permanent deformation of either said spline or seat members.

2. A spline and seat connector assembly as defined in claim 1 wherein said peripheral wall is in the shape of a rectangle.

3. A spline and seat connector assembly as defined in claim 2 wherein the end walls of said rectangles are arcuately shaped and have a sufi'lciently thin cross section to allow the side walls to be resiliently compressed toward each other.

4. A spline and seat connector assembly as defined in claim 1 wherein each sidewall has a group of at least three adjacent toothlike projections and the distances across the spline member between the outer tooth edges of the projections on opposite sidewalls increases progressively as the distance of the tooth edge increases from that end of the spline member.

5. A spline and seat connector assembly as defined in claim 1 wherein the peripheral wall is in the general shape of a circle.

6. A spline and seat connector assembly as defined in claim 5 wherein the peripheral wall is generally circular but with reentrant reverse bend portions located along said central plane.

7. A spline and seat connector assembly as defined in claim 1 wherein said seat member contains double sidewalls, one being an inner wall and the other being an outer body wall, separated by a void allowing deflection of the exposed inner sidewall relative to the body wall of the seat member in a direction parallel to said centralplane and the toothlike projections on said spline member snapping into locking position upon insertion of said spline member into said seat member to pull the spline joint more tightly together.

8. A spline and seat connector assembly as defined in claim 1 wherein the seat member contains double sidewalls, an inner wall and an outer body wall separated by a void allowing deflection of the exposed inner sidewall relative to the body wall of the seat member in a direction perpendicular to said central longitudinal plane.

9. A spline and seat connector assembly as defined in claim 1 wherein the seat member is provided with an intermediate insert between the spline member sidewall and the seat member sidewall, said insert with directional teeth cooperating with said spline member teeth and more sharply angled serrations cooperating with the seat member wall in such a way as to wedge the insert against the spline member and hold the spline more tightly upon attempted removal of the spline.

10. A spline and seat connector assembly as defined in claim 9 wherein said insert is hinged as a flap on said seat member to protect the seat member prior to insertion of the spline member and to fold down into the seat member into abutting relationship between said spline member sidewall and said seat member sidewall.

11. A spline and seat connector assembly as defined in claim 1 wherein each of said members has a plurality of parallel toothlike projections on each sidewall, the pitch of the toothlike projections on one of said members is an integer multiple of the pitch of corresponding toothlike projections on the other of said members.

12. A spline and seat connector assembly as defined in claim 11 wherein the pitch of the toothlike projections on the spline member is greater than the pitch of the projections on the seat member to thereby cause a spline member to ratchet into position in said seat member.

13. A spline and seat connector assembly as defined in claim 1 wherein the seat member has a cross-sectional configuration which effects compression of its sidewalls against the spline member sidewalls during said attempted withdrawal.

[4. A spline and seat connector assembly comprising:

a continuous and longitudinally extending, substantially hollow spline member having a longitudinally extending axis and a pair of sidewalls on opposite sides of a central longitudinal plane of the spline member passing through the longitudinal axis of said spline member, said sidewalls having outwardly facing surfaces containing longitu dinally extending, rigid, toothlike projections thereon with outwardly extending locking surfaces and wherein each tip of said toothlike projections lies coincident with an imaginary line extending substantially parallel to said longitudinal axis of said spline member and said spline member has a length several times greater than any of its lateral dimensions;

a longitudinally extending seat member having a longitudinal axis lying in the same longitudinal plane as the central longitudinal plane of the spline member, and parallel to the longitudinal axis of said spline member and comprising a pair of sidewalls on opposite sides of said longitudinal plane and defining a spline member receiving recess having a length several times greater than any of its lateral dimensions, said sidewalls having inwardly facing surfaces provided with longitudinally extending, rigid, toothlike projections with locking surfaces engaging the locking surfaces of said spline member, said seat member sidewalls being spaced apart by a distance substantially equal to the distance between said spline member sidewalls, said seat member having an arcuate end wall extending between said seat sidewall; and

said assembly being characterized by said spline and seat members having a combined sutficient resilient deflection of their respective sidewalls to enable insertion of the spline member into the desired locking engagement position in the seat member by movement of said spline member relative to said seat member parallel to said longitudinal plane in a direction normal to said longitudinal axes without permanent deformation of either said spline or seat members.

15. A spline and seat connector assembly as defined in claim 14 wherein said spline member has an H-shaped configuration with the upper end of the H forming one spline member and the lower end of the H forming a second spline member.

16. A spline and seat connector assembly as defined in claim 14 wherein said spline member has an S-shaped configuration including a central leg and crosses the joint between two opposed seat members along each seat member sidewall and also at a third position intermediate said sidewalls to thereby place said central leg under compression during any attempted withdrawal.

17. A spline and seat connector assembly as defined in claim 14 wherein said spline member has a T-shaped configuration on at least one end having a central stem parallel to said central plane and a cross arm adjacent one end of said stem,

'. said cross arm having free end portions which extend over a portion of said stem and are bendable inwardly during the insertion of said spline member into said seat member and bendable outwardly during attempted withdrawal.

18. A spline and seat connector assembly as defined in claim 14 wherein said peripheral wall is in the shape of a rectangle.

19. A spline and seat connector assembly as defined in claim 14 wherein the peripheral wall is in the general shape of a circle.

20. A spline and seat connector assembly as defined in claim 14 wherein the spline member has an elongated C- shaped cross section with opposed teeth at opposite ends of the cross-sectional configuration to provide a double-ended spline member.

i I I II 

1. A spline and seat connector assembly comprising: a longitudinally extending spline member having a closed peripheral wall and a hollow interior, said peripheral wall having two sidewalls symmetrically disposed on opposite sides of a central longitudinal plane, said sidewalls having outwardly facing surfaces containing two sets of longitudinally extending, rigid, toothlike projections on each of said sidewalls, a first set of projections defining one end of said spline member, and a second set of projections defining the other end of said spline member, the locking surfaces of the projections on opposite ends of said spline member being reversely disposed; a longitudinally extending seat member having a longitudinal axis lying in the same longitudinal plane as the central longitudinal plane of the spline member comprising a pair of sidewalls on opposite sides of said longitudinal plane and defining a spline member receiving recess, said sidewalls having inwardly facing surfaces provided with longitudinally extending, rigid, toothlike projections with locking surfaces engaging the locking surfaces on said spline member, said seat member sidewalls being spaced apart by a distance substantially equal to the distance between said spline member sidewalls; and said assembly being characterized by said spline and said seat members having a combined sufficient resilient deflection of their respective sidewalls to enable insertion of the spline member into the desired locking engagement position in the seat member by movement of said spline member relative to said seat member parallel to said longitudinal plane in a direction normal to said longitudinal axis without permanent deformation of either said spline or seat members.
 2. A spline and seat connector assembly as defined in claim 1 wherein said peripheral wall is in the shape of a rectangle.
 3. A spline and seat connector assembly as defined in claim 2 wherein the end walls of said rectangles are arcuately shaped and have a sufficiently thin cross section to allow the side walls to be resiliently compressed toward each other.
 4. A spline and seat connector assembly as defined in claim 1 wherein each sidewall has a group of at least three adjacent toothlike projections and the distances across the spline member between the outer tooth edges of the projections on opposite sidewalls increases progressively as the distance of the tooth edge increases from that end of the spline member.
 5. A spline and seat connector assembly as defined in claim 1 wherein the peripheral wall is in the general shape of a circle.
 6. A spline and seat connector assembly as defined in claim 5 wherein the peripheral wall is generally circular but with reentrant reverse bend portions located along said central plane.
 7. A spline and seat connector assembly as defined in claim 1 wherein said seat member contains double sidewalls, one being an inner wall and the other being an outer body wall, separated by a void allowing deflection of the exposed inner sidewall relative to the body wall of the seat member in a direction parallel to said central plane and the toothlike projections on said spline member snapping into locking position upon insertion of said spLine member into said seat member to pull the spline joint more tightly together.
 8. A spline and seat connector assembly as defined in claim 1 wherein the seat member contains double sidewalls, an inner wall and an outer body wall separated by a void allowing deflection of the exposed inner sidewall relative to the body wall of the seat member in a direction perpendicular to said central longitudinal plane.
 9. A spline and seat connector assembly as defined in claim 1 wherein the seat member is provided with an intermediate insert between the spline member sidewall and the seat member sidewall, said insert with directional teeth cooperating with said spline member teeth and more sharply angled serrations cooperating with the seat member wall in such a way as to wedge the insert against the spline member and hold the spline more tightly upon attempted removal of the spline.
 10. A spline and seat connector assembly as defined in claim 9 wherein said insert is hinged as a flap on said seat member to protect the seat member prior to insertion of the spline member and to fold down into the seat member into abutting relationship between said spline member sidewall and said seat member sidewall.
 11. A spline and seat connector assembly as defined in claim 1 wherein each of said members has a plurality of parallel toothlike projections on each sidewall, the pitch of the toothlike projections on one of said members is an integer multiple of the pitch of corresponding toothlike projections on the other of said members.
 12. A spline and seat connector assembly as defined in claim 11 wherein the pitch of the toothlike projections on the spline member is greater than the pitch of the projections on the seat member to thereby cause a spline member to ratchet into position in said seat member.
 13. A spline and seat connector assembly as defined in claim 1 wherein the seat member has a cross-sectional configuration which effects compression of its sidewalls against the spline member sidewalls during said attempted withdrawal.
 14. A spline and seat connector assembly comprising: a continuous and longitudinally extending, substantially hollow spline member having a longitudinally extending axis and a pair of sidewalls on opposite sides of a central longitudinal plane of the spline member passing through the longitudinal axis of said spline member, said sidewalls having outwardly facing surfaces containing longitudinally extending, rigid, toothlike projections thereon with outwardly extending locking surfaces and wherein each tip of said toothlike projections lies coincident with an imaginary line extending substantially parallel to said longitudinal axis of said spline member and said spline member has a length several times greater than any of its lateral dimensions; a longitudinally extending seat member having a longitudinal axis lying in the same longitudinal plane as the central longitudinal plane of the spline member, and parallel to the longitudinal axis of said spline member and comprising a pair of sidewalls on opposite sides of said longitudinal plane and defining a spline member receiving recess having a length several times greater than any of its lateral dimensions, said sidewalls having inwardly facing surfaces provided with longitudinally extending, rigid, toothlike projections with locking surfaces engaging the locking surfaces of said spline member, said seat member sidewalls being spaced apart by a distance substantially equal to the distance between said spline member sidewalls, said seat member having an arcuate end wall extending between said seat sidewall; and said assembly being characterized by said spline and seat members having a combined sufficient resilient deflection of their respective sidewalls to enable insertion of the spline member into the desired locking engagement position in the seat member by movement of said spline member relative to said seat member parallel to said longitudinal plane in a direction normal to said lOngitudinal axes without permanent deformation of either said spline or seat members.
 15. A spline and seat connector assembly as defined in claim 14 wherein said spline member has an H-shaped configuration with the upper end of the H forming one spline member and the lower end of the H forming a second spline member.
 16. A spline and seat connector assembly as defined in claim 14 wherein said spline member has an S-shaped configuration including a central leg and crosses the joint between two opposed seat members along each seat member sidewall and also at a third position intermediate said sidewalls to thereby place said central leg under compression during any attempted withdrawal.
 17. A spline and seat connector assembly as defined in claim 14 wherein said spline member has a T-shaped configuration on at least one end having a central stem parallel to said central plane and a cross arm adjacent one end of said stem, said cross arm having free end portions which extend over a portion of said stem and are bendable inwardly during the insertion of said spline member into said seat member and bendable outwardly during attempted withdrawal.
 18. A spline and seat connector assembly as defined in claim 14 wherein said peripheral wall is in the shape of a rectangle.
 19. A spline and seat connector assembly as defined in claim 14 wherein the peripheral wall is in the general shape of a circle.
 20. A spline and seat connector assembly as defined in claim 14 wherein the spline member has an elongated C-shaped cross section with opposed teeth at opposite ends of the cross-sectional configuration to provide a double-ended spline member. 